Long-Term Debt and Capital Lease - Schedule of Long-term Debt (Details) - USD ($)	May 31, 2017	May 31, 2016
Face value of long-term debt	$ 18,032,416	$ 15,446,748
Debt issue costs, net of amortization	(228,426)	(69,185)
Debt	17,803,990	15,377,563
Less: Current portion	(2,493,236)	(2,088,327)
Long-term Debt	15,310,754	13,289,236
Term Note A Payable To International Bank of Commerce, Prime Rate of Interest Plus 0.5% But Not Less Than 4.0%, Maturing January 7, 2019 [Member]
Long-term debt gross	4,626,191	5,310,179
Term Note B Payable To International Bank of Commerce, Prime Rate of Interest Plus 0.5% But Not Less Than 4.0%, Maturing January 7, 2019 [Member]
Long-term debt gross	1,715,132	2,688,659
Revolving Note Payable to International Bank of Commerce, Prime Rate of Interest Plus 0.5% But Not Less Than 4.0%, Due January 31, 2019 [Member]
Long-term debt gross	2,260,000	1,675,000
Term Note Payable by GRE to International Bank of Commerce, Interest Rate of 4.5%, Monthly Principal and Interest Payments of $26,215, Due January 31, 2019 [Member]
Long-term debt gross	2,841,285	3,021,734
Note Payable to Robert Rosene, 7.5% Interest, Due January 15, 2019 [Member]
Long-term debt gross	4,469,355	2,066,000
Note payable to First Bank, Prime Rate of Interest Plus 1.45% but not Less Than 4.95%, Monthly Principal and Interest Payments of $30,628, Due August 21, 2021, Secured by Equipment [Member]
Long-term debt gross	1,396,448
Note Payable to Yorktown Management & Financial Services, LLC, 5.0% Interest, Due February 28, 2019, Monthly Principal and Interest Payments of $20,629 [Member]
Long-term debt gross	413,969	634,616
Other Note Payable [Member]
Long-term debt gross	$ 310,036	$ 50,560